U.S. patent application number 10/536383 was filed with the patent office on 2006-08-17 for ink-jet recording material.
This patent application is currently assigned to MITSUBISHI PAPER MILLS LIMITED. Invention is credited to Hideaki Ishiguro, Shuzo Kinoshita, Hideto Kiyama, Hiroshi Sakaguchi, Kazuhiko Sunada.
Application Number | 20060182903 10/536383 |
Document ID | / |
Family ID | 32396271 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060182903 |
Kind Code |
A1 |
Sakaguchi; Hiroshi ; et
al. |
August 17, 2006 |
Ink-jet recording material
Abstract
The present invention discloses an ink-jet recording material
having a support and at least two ink-receptive layers containing
inorganic fine particles and a hydrophilic binder, which comprises
an ink-receptive layer A nearer to the support containing
precipitated silica fine particles having an average secondary
particle diameter 500 nm or less, or precipitated silica fine
particles having an average secondary particle diameter 500 nm or
less and fumed silica fine particles having an average secondary
particle diameter 500 nm or less, and containing less than 20 parts
by weight of a polyvinyl alcohol based on 100 parts by weight of
the whole silica fine particles in the ink-receptive layer A, and
an ink-receptive layer B farther from the support containing at
least one kind of fine particles selected from fumed silica,
alumina and alumina hydrate and less than 25 parts by weight of a
polyvinyl alcohol based on 100 parts by weight of the fine
particles.
Inventors: |
Sakaguchi; Hiroshi; (TOKYO,
JP) ; Sunada; Kazuhiko; (Tokyo, JP) ; Kiyama;
Hideto; (Tokyo, JP) ; Ishiguro; Hideaki;
(Tokyo, JP) ; Kinoshita; Shuzo; (Tokyo,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
MITSUBISHI PAPER MILLS
LIMITED
4-2, MARUNOUCHI 3-CHOME. CHIYODA-KU
TOKYO
JP
100-0005
|
Family ID: |
32396271 |
Appl. No.: |
10/536383 |
Filed: |
November 27, 2003 |
PCT Filed: |
November 27, 2003 |
PCT NO: |
PCT/JP03/15142 |
371 Date: |
February 28, 2006 |
Current U.S.
Class: |
428/32.24 |
Current CPC
Class: |
B41M 5/502 20130101;
B41M 5/5254 20130101; B41M 5/5218 20130101 |
Class at
Publication: |
428/032.24 |
International
Class: |
B41M 5/00 20060101
B41M005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 27, 2002 |
JP |
2002-343238 |
Feb 24, 2003 |
JP |
2003-045753 |
Claims
1. An ink-jet recording material having a support and at least two
ink-receptive layers each containing inorganic fine particles and a
hydrophilic binder, which comprises an ink-receptive layer A nearer
to the support containing precipitated silica fine particles having
an average secondary particle diameter 500 nm or less, or
precipitated silica fine particles having an average secondary
particle diameter 500 nm or less and fumed silica fine particles
having an average secondary particle diameter 500 nm or less, and
containing less than 20 parts by weight of a polyvinyl alcohol
based on 100 parts by weight of the whole silica fine particles in
the ink-receptive layer A, and an ink-receptive layer B farther
from the support containing at least one kind of fine particles
selected from fumed silica, alumina and alumina hydrate and less
than 25 parts by weight of a polyvinyl alcohol based on 100 parts
by weight of the fine particles.
2. The ink-jet recording material according to claim 1, wherein the
precipitated silica fine particles having an average secondary
particle diameter of 500 nm or less are fine particles in which
precipitated silica is pulverized to have an average secondary
particle diameter of 500 nm or less in an aqueous medium.
3. The ink-jet recording material according to claim 2, wherein the
fine particles in which the precipitated silica is pulverized are
fine particles in which precipitated silica having an average
secondary particle diameter of 5 .mu.m or more is pulverized by
using media mill in the presence of a cationic compound in an
aqueous medium.
4. The ink-jet recording material according to claim 3, wherein an
oil absorption amount of the precipitated silica is 210 ml/100 g or
less.
5. The ink-jet recording material according to claim 1, wherein the
fumed silica fine particles having an average secondary particle
diameter of 500 nm or less are fine particles in which fumed silica
is pulverized to have an average secondary particle diameter of 500
nm or less in the presence of a cationic compound in an aqueous
medium.
6. The ink-jet recording material according to claim 1, wherein a
weight ratio of the precipitated silica fine particles and fumed
silica fine particles contained in the ink-receptive layer A is
30:70 to 70:30.
7. The ink-jet recording material according to claim 1, wherein the
ink-receptive layer A contains boric acid or a borate.
8. The ink-jet recording material according to claim 1, wherein a
dry coated amount of the ink-receptive layer B containing the fumed
silica is 4 g/m.sup.2 or less in an amount of the fumed silica
9. The ink-jet recording material according to claim 1, wherein the
ink-receptive layer B contains boric acid or a borate.
10. The ink-jet recording material according to claim 1, wherein
the alumina hydrate is a plate shaped alumina hydrate having an
aspect ratio of 2 or more.
11. The ink-jet recording material according to claim 1, wherein
the alumina hydrate is pseudoboehmite.
12. The ink-jet recording material according to claim 1, wherein
the alumina is .gamma.-alumina.
13. The ink-jet recording material according to claim 1, wherein a
layer mainly comprising colloidal silica is further provided on the
ink-receptive layer B.
14. The ink-jet recording material according to claim 1, wherein
the support is a water-resistant support.
Description
TECHNICAL FIELD
[0001] The present invention relates to an ink-jet recording
material for recording in an ink-jet recording system such as an
ink-jet printer, etc., more specifically to an ink-jet recording
material having high glossiness, excellent in color forming
property, less color blur that generates during preservation after
printing with a dye ink, excellent in ink-absorption property and
resistance to crack by folding, and further excellent in flaw
resistance, and less surface defects caused by accompanying with
multi-layer coating.
BACKGROUND ART
[0002] As the recording material to be used for an ink-jet
recording system, a usual paper or a recording material in which a
porous ink-receptive layer comprising a pigment such as amorphous
silica, etc., and a hydrophilic binder such as a polyvinyl alcohol,
etc. is provided on a support that is so-called ink-jet recording
paper has been known.
[0003] For example, a recording material obtained by coating a
silicon-containing pigment such as silica, etc. with a hydrophilic
binder on a paper support has been used. Also, there has been
disclosed to use silica fine particles in which precipitated silica
agglomerate had been pulverized to 10 to 300 nm by a mechanical
means (for example, see Japanese Unexamined Patent Publications No.
Hei. 9-286165, No. Hei. 10-181190). However, these recording
materials are not yet sufficiently satisfied in a surface
glossiness and coloring property to be obtained for a photo-like
recording material which is an object of the present invention.
[0004] On the other hand, it has been proposed a recording material
in which the ink-receptive layer is made a two-layer structure, and
the upper layer is made a layer having a relatively higher
glossiness. For example, it has been known a recording material in
which a layer containing colloidal silica, alumina or alumina
hydrate is provided as a gloss providing layer on an ink-receptive
layer mainly comprising an inorganic pigment, etc. (see, for
example, Japanese Unexamined Patent Publications No. 2000-37944 and
No. Hei.7-89216). Also, it has been proposed a recording material
in which pulverized amorphous synthetic silica is contained in a
lower layer, and a layer containing fumed silica is provided at an
upper layer (see, for example, Japanese Unexamined Patent
Publication No. 2001-80204), or a recording material in which
pulverized gel method silica is contained in a lower layer, and an
upper layer containing fumed silica or alumina is provided (see,
for example, Japanese Unexamined Patent Publication No.
2001-277712), and further, there is disclosed a recording material
in which a lower layer containing fumed silica and an upper layer
containing alumina or alumina hydrate are provided (see, for
example, WO 02/34541 A1).
[0005] On the other hand, accompanying with high quality in image
of an ink-jet printer, printing which is equal to a silver salt
photograph can be realized. For example, to realize a photo-like
image, a recording system with higher image quality has been
proposed in an ink-jet printer side, by using a light color ink
which is so-called photo ink, or an intermediate color ink such as
gray, dark yellow, etc., and commercially available.
[0006] As a recording material for photography, it has not yet been
satisfied by the above-mentioned recording material, and further
improvement in glossiness and coloring property has been desired.
Also, when printing is carried out by using dye ink, a recording
material prevented from color blur caused during preservation has
been desired. Also, more improved ink absorption property has been
desired. It is an effective means to realize higher ink absorption
property that an ink-receptive layer is thickened, but it involves
the problem that crack (crack by folding) occurs at an
ink-receptive layer even when slightly bending the recording
material at the time of handling the same. This is because the
recording material has a constitution in which an ink-receptive
layer is inherently high brittleness to ensure high ink absorption
property to the recording material, and yet the coating layer with
high brittleness is made thick.
[0007] As a means to prevent from causing the above-mentioned crack
by folding, it is effective to make little a ratio of an inorganic
pigment/a binder in the ink-receptive layer or reduce an amount of
boric acid or a borate to be added which is added as a
cross-linking agent of the binder. However, according to the means
to make an inorganic pigment/binder ratio little, an ink absorption
property becomes worse. Also, according to the means to decrease an
amount of boric acid or a borate to be added, worsening in an ink
absorption property occurs, and further, glossiness sometimes
lowers or uneven glossiness sometimes occurs.
[0008] Moreover, there is a problem in these two-layer constitution
recording materials that coating defects such as cracking, etc.
increase in the preparation process. Whereas it is uncertain about
the mechanism of causing the coating defects, it is estimated to be
caused by subjecting to multi-layer coating two layers with
different shrinkage rates at drying. Japanese Unexamined Patent
Publication No. 2003-211824 discloses a technique of using
precipitated silica and fumed silica in combination. However, that
disclosed therein is to provide an ink-jet recording material with
a low cost by making a coating solution high concentration, and
there is neither suggested nor disclosed to avoid disorder
accompanied by multi-layer coating.
[0009] An object of the present invention is to provide an ink-jet
recording material having high glossiness and excellent in color
forming property, and causes less color blur which occurs during
preservation after printing with dye ink. The second object is to
provide an ink-jet recording material which is excellent in ink
absorption property, coloring property, and resistance to crack by
folding, and further excellent in glossiness and flaw resistance.
The third object is to provide an ink-jet recording material which
causes a little surface defect which occurs accompanying with
multi-layer coating.
DISCLOSURE OF THE INVENTION
[0010] The above-mentioned objects of the present invention can be
accomplished by the following ink-jet recording material.
[0011] 1. An ink-jet recording material having a support and at
least two ink-receptive layers containing inorganic fine particles
and a hydrophilic binder, which comprises an ink-receptive layer A
nearer to the support containing precipitated silica fine particles
having an average secondary particle diameter 500 nm or less, or
precipitated silica fine particles having an average secondary
particle diameter 500 nm or less and fumed silica fine particles
having an average secondary particle diameter 500 nm or less, and
containing less than 20 parts by weight of a polyvinyl alcohol
based on 100 parts by weight of the whole silica fine particles in
the ink-receptive layer A, and an ink-receptive layer B farther
from the support containing at least one kind of fine particles
selected from fumed silica, alumina and alumina hydrate and less
than 25 parts by weight of a polyvinyl alcohol based on 100 parts
by weight of the fine particles.
[0012] 2. The ink-jet recording material according to the
above-mentioned 1, wherein the precipitated silica fine particles
having an average secondary particle diameter of 500 nm or less are
fine particles in which precipitated silica is pulverized to have
an average secondary particle diameter of 500 nm or less in an
aqueous medium.
[0013] 3. The ink-jet recording material according to the
above-mentioned 2, wherein the fine particles in which the
precipitated silica is pulverized are fine particles in which
precipitated silica having an average secondary particle diameter
of 5 .mu.m or more is pulverized by using media mill in the
presence of a cationic compound in an aqueous medium.
[0014] 4. The ink-jet recording material according to the
above-mentioned 3, wherein an oil absorption amount of the
precipitated silica is 210 ml/100 g or less.
[0015] 5. The ink-jet recording material according to the
above-mentioned 1, wherein the fumed silica fine particles having
an average secondary particle diameter of 500 nm or less are fine
particles in which fumed silica is pulverized to have an average
secondary particle diameter of 500 nm or less in the presence of a
cationic compound in an aqueous medium.
[0016] 6. The ink-jet recording material according to the
above-mentioned 1, wherein a weight ratio of the precipitated
silica fine particles and fumed silica fine particles contained in
the ink-receptive layer A is 30:70 to 70:30.
[0017] 7. The ink-jet recording material according to the
above-mentioned 1, wherein the ink-receptive layer A contains boric
acid or a borate.
[0018] 8. The ink-jet recording material according to the
above-mentioned 1, wherein a dry coated amount of the ink-receptive
layer B containing the fumed silica is 4 g/m.sup.2 or less in an
amount of the fumed silica.
[0019] 9. The ink-jet recording material according to the
above-mentioned 1, wherein the ink-receptive layer B contains boric
acid or a borate.
[0020] 10. The ink-jet recording material according to the
above-mentioned 1, wherein the alumina hydrate is a plate shaped
alumina hydrate having an aspect ratio of 2 or more.
[0021] 11. The ink-jet recording material according to the
above-mentioned 1, wherein the alumina hydrate is
pseudoboehmite.
[0022] 12. The ink-jet recording material according to the
above-mentioned 1, wherein the alumina is .gamma.-alumina.
[0023] 13. The ink-jet recording material according to the
above-mentioned 1, wherein a layer mainly comprising colloidal
silica is further provided on the ink-receptive layer B.
[0024] 14. The ink-jet recording material according to the
above-mentioned 1, wherein the support is a water-resistant
support.
BEST MODE FOR CARRYING OUT THE INVENTION
[0025] In the following, the present invention is explained in
detail.
[0026] As the support to be used in the present invention, there
may be used a film such as a polyethylene, polypropylene, polyvinyl
chloride, diacetate resin, triacetate resin, cellophane, acrylic
resin, polyethyleneterephthalate, polyethylenenaphthalate, etc., a
water-resistant support such as a resin-coated paper, etc., and a
water-absorptive support such as uncoated paper, art paper, coated
paper, cast-coated paper, etc. Preferably used is a water-resistant
support. In particular, a thickness of these supports having about
50 to 250 .mu.m or so is preferably used.
[0027] Silica fine particles to be used in the present invention is
amorphous synthetic silica, and the amorphous synthetic silica can
be roughly classified into fumed silica, wet process silica, and
others according to the preparation method. Fumed silica is also
called to as the dry process silica, and it can be generally
prepared by a flame hydrolysis method. More specifically, it has
generally been known a method in which silicon tetrachloride is
burned with hydrogen and oxygen, and the fumed silica is
commercially available from Nippon Aerosil K. K. (Japan) under the
trade name of Aerosil, and K. K. Tokuyama (Japan) under the trade
name of QS type, etc.
[0028] The wet process silica can be further classified into a
precipitation method silica, a gel method silica and a sol method
silica according to the preparation processes. The precipitation
method silica can be prepared by reacting sodium silicate and
sulfuric acid under alkali conditions, silica particles grown in
particle size aggregated and precipitated, and then, they are
processed through filtration, washing, drying, pulverization and
classification to prepare a product. The silica secondary particles
prepared by the method form softly agglomerated particles and
particles that can be relatively easily pulverized can be obtained.
As the precipitation method silica, it is commercially available
from NIPPON SILICA CORPORATION as Nipsil, and K. K. Tokuyama as
Tokusil or Finesil. The gel method silica can be produced by
reacting sodium silicate and sulfuric acid under acidic conditions.
In this method, small silica particles are dissolved during
ripening and so reprecipitated between other primary particles
which are larger sized particles that primary particles are
combined to each other. Thus, clear primary particles disappear and
form relatively hard agglomerated particles having inner void
structure. For example, it is commercially available from Mizusawa
Industrial Chemicals, Ltd. as Mizukasil, or Grace Japan Co., Ltd.
as Sylojet. The sol method silica is also called to as colloidal
silica and can be obtained by heating and ripening silica sol
obtained by methathesis of sodium silicate by an acid, etc., or
passing through an ion-exchange resin layer, and is commercially
available from, for example, Nissan Chemical Industries, Ltd. as
SNOWTEX.
[0029] In the ink-receptive layer A of the present invention,
precipitated silica having an average secondary particle diameter
of 500 nm or less is contained. The precipitated silica produced by
the conventional method has an average secondary particle diameter
of 1 .mu.m or more, so that those of the silica pulverized to have
500 nm or less are used. As a pulverizing method, a wet type
dispersing method in which silica dispersed in an aqueous medium is
mechanically pulverized can be preferably used. As the wet type
dispersing machine, a media mill such as a ball mill, a beads mill,
a sand grinder, etc., a pressure type dispersing device such as a
high-pressure homogenizer, an ultra high-pressure homogenizer,
etc., an ultrasonic wave dispersing device, and a thin-film spin
type dispersing device, etc., may be used, and in the present
invention, use of a media mill such as a ball mill is particularly
preferred.
[0030] The precipitated silica to be used in the ink-receptive
layer A of the present invention preferably has an average primary
particle diameter of 50 nm or less, particularly preferably 3 to 40
nm. Also, an oil absorption amount of the precipitated silica
according to the present invention is preferably in the range of
120 to 210 ml/100 g, and the range of 160 to 210 ml/100 g is
particularly preferred. The oil absorption amount can be measured
based on the description of JIS K-5101.
[0031] Pulverization of the precipitated silica in the present
invention is preferably carried out in the presence of a cationic
compound. When the cationic compound is added to silica dispersed
in water, agglomerated products frequently occur, but by subjecting
the resulting material to pulverization treatment, dispersion with
a higher concentration can be realized than they are dispersed only
in water, and as a result, dispersion efficiency is increased so
that they can be pulverized to finer particles. Moreover, by using
a high concentration dispersion, it is possible to make a coating
solution a higher concentration at the time of preparing the
coating solution, and thus, there are merits that a production
efficiency is improved. In particular, if the precipitated silica
having an average secondary particle diameter of 5 .mu.m or more is
used at this time, increase in viscosity due to occurrence of
agglomerated material at the initial stage can be prevented and
dispersion with a higher concentration can be realized so that it
is more advantageous. An upper limit of the average secondary
particle diameter is not specifically limited, and the average
secondary particle diameter of the precipitated silica is generally
200 .mu.m or less.
[0032] As the cationic compound, a cationic polymer or a
water-soluble metallic compound can be used. As the cationic
polymer, polyethyleneimine, polydiallylamine, polyallylamine,
polyalkylamine, as well as polymers having a primary to tertiary
amino group or a quaternary ammonium group as disclosed in Japanese
Unexamined Patent Publications No. Sho. 59-20696, No. Sho.
59-33176, No. Sho. 59-33177, No. Sho. 59-155088, No. Sho. 60-11389,
No. Sho. 60-49990, No. Sho. 60-83882, No. Sho. 60-109894, No. Sho.
62-198493, No. Sho. 63-49478, No. Sho. 63-115780, No. Sho.
63-280681, No. Hei. 1-40371, No. Hei. 6-234268, No. Hei. 7-125411
and No. Hei. 10-193776, etc. Incidentally, these polymers may be a
salt such as ammonium chloride, etc., when they are possible. In
particular, a diallylamine derivative is preferably used as the
cationic polymer. An average molecular weight of these cationic
polymers is preferably 2,000 to 100,000 or so, particularly
preferably 2,000 to 30,000 or so. If the molecular weight is larger
than 100,000, the dispersion has higher viscosity so that it is not
preferred.
[0033] As the water-soluble metallic compound, there may be
mentioned, for example, a water-soluble polyvalent metal salt.
There may be mentioned a water-soluble salt of a metal selected
from calcium, barium, manganese, copper, cobalt, nickel, aluminum,
iron, zinc, titanium, zirconium, chromium, magnesium, tungsten, and
molybdenum. More specifically, there may be mentioned, for example,
calcium acetate, calcium chloride, calcium formate, calcium
sulfate, barium acetate, barium sulfate, barium phosphate,
manganese chloride, manganese acetate, manganese formate dihydrate,
manganese ammonium sulfate hexahydrate, cupric chloride, copper
(II) ammonium chloride dihydrate, copper sulfate, cobalt chloride,
cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate,
nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel
ammonium sulfate hexahydrate, nickel amidesulfate tetrahydrate,
aluminum sulfate, aluminum sulfite, aluminum thiosulfate,
polyaluminum chloride, aluminum nitrate nonahydrate, aluminum
chloride hexahydrate, ferrous bromide, ferrous chloride, ferric
chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc
chloride, zinc nitrate hexahydrate, zinc sulfate, zinc
p-phenolsulfbnate, titanium chloride, titanium sulfate, titanium
lactate, zirconium acetate, zirconium chloride, zirconium
oxychloride octahydrate, zirconium hydroxy-chloride, chromium
acetate, chromium sulfate, magnesium sulfate, magnesium chloride
hexahydrate, magnesium citrate nonahydrate, sodium
phosphotungstate, tungsten sodium citrate,
dodecawolframatophosphate n hydrate, dodecawolframatosilicate 26
hydrate, molybdenum chloride, dodecamolybdatephosphate n hydrate,
etc.
[0034] Of the above-mentioned water-soluble polyvalent metallic
compounds, a compound comprising aluminum or a metal belonging to
Group 4a (for example, zirconium, titanium) of the Periodic Table
is preferred. Particularly preferred is a water-soluble aluminum
compound. As the water-soluble aluminum compound, it has been known
as an inorganic salt, for example, aluminum chloride or a hydrate
thereof, aluminum sulfate or a hydrate thereof, aluminum alum, etc.
Moreover, it has been known a basic poly(aluminum hydroxide)
compound which is an inorganic aluminum-containing cationic
polymer, and it is preferably used.
[0035] A main component of the above-mentioned basic poly(aluminum
hydroxide) compound is shown by the following formula 1, 2 or 3,
and is a water-soluble poly(aluminum hydroxide) containing a
polynuclear condensed ion which is basic and a polymer in a stable
form, such as [Al.sub.6(OH).sub.15].sup.3+,
[Al.sub.8(OH).sub.20].sup.4+, [Al.sub.13(OH).sub.34].sup.5+,
[Al.sub.21(OH).sub.60].sup.3+, etc. [Al.sub.2
(OH).sub.nCl.sub.6-n].sub.m Formula 1
[Al(OH).sub.3].sub.nAlCl.sub.3 Formula 2
Al.sub.n(OH).sub.mCl.sub.(3n-m)0<m<3n Formula 3
[0036] These compounds are commercially available from Taki
Chemical, K. K. under the name of poly(aluminum chloride) (PAC) as
a water treatment agent, from Asada Chemical K. K. under the name
of poly(aluminum hydroxide) (Paho), and from K. K. Riken Green
under the name of Pyurakemu W T, and from other manufacturers with
the same objects, whereby various kinds of different grades can be
easily obtained.
[0037] As the water-soluble compound containing an element
belonging to Group 4a of the Periodic Table to be used in the
present invention, a water-soluble compound containing titanium or
zirconium is more preferred. As the watersoluble compound
containing titanium, there may be mentioned titanium chloride and
titanium sulfate. As the water-soluble compound containing
zirconium, there may be mentioned zirconium acetate, zirconium
chloride, zirconium oxychloride, zirconium hydroxychloride,
zirconium nitrate, basic zirconium carbonate, zirconium hydroxide,
zirconium lactate, zirconium-ammonium carbonate,
zirconium-potassium carbonate, zirconium sulfate, zirconium
fluoride compound, etc. In the present invention, the term
"water-soluble" means that a compound is soluble in water at normal
temperature and normal pressure in an amount of 1% by weight or
more.
[0038] A concrete method to obtain precipitated silica fine
particles having an average secondary particle diameter of 500 nm
or less according to the present invention comprises firstly adding
at least one of silica and a cationic polymer and/or a cationic
metallic compound into water and dispersing them by using at least
one dispersing device such as a saw blade type dispersing device, a
propeller blade type dispersing device, or a rotor stator type
dispersing device and the like to obtain a provisional dispersion.
Here, as a method of addition, it is preferred to add the
precipitated silica particles as powder into water in which the
cationic compound had previously been contained. If necessary, a
suitably amount of a solvent with a low boiling point, etc. may be
further added. An amount of the cationic polymer or the
water-soluble metallic compound is preferably 0.5 to 20 parts by
weight, more preferably 2 to 10 parts by weight based on 100 parts
by weight of the silica. By making the above range, a viscosity of
the silica provisional dispersion is not too high, and a
concentration of the solid content can be made high. The
concentration of the solid content of the silica provisional
dispersion according to the present invention is preferably higher,
but it is too high concentration, dispersion cannot be carried out,
so that the preferred range is 20 to 60% by weight, more preferably
30 to 50% by weight.
[0039] The silica provisional dispersion obtained by the
above-mentioned method is subjected to pulverization treatment with
a bead mill. The bead mill means a device in which beads are filled
in an apparatus having a stirring device therein, a liquid material
is charged in the apparatus and the stirring device is rotated to
collide beads with each other whereby a shearing force is applied
to the liquid material to pulverize the same. A particle size of
the beads is generally 0.1 to 10 mm, preferably 0.2 to 1 mm, more
preferably 0.3 to 0.6 mm. As the beads, there are glass beads,
ceramics beads, metal beads, etc., and zirconia beads are preferred
in the points of abrasion resistance and dispersion efficiency.
Also, a filling ratio of the beads to be added into an apparatus is
generally 40 to 80% by volume, preferably 55 to 80% by volume.
According to the above-mentioned dispersing conditions, a silica
dispersion can be pulverized to particles having an average
secondary particle diameter of 500 nm or less with good efficiency,
without remaining coarse grains or generating agglomerated
material. When the provisional dispersion is treated continuously
and when coarse grains likely remain with a number of passing time
being one, it is preferably treated twice or more. In the present
invention, it is preferred that a concentration is high in the
range in which coarse grains are not generated, since a coating
solution can be made higher concentration. A concentration of the
solid content of the silica dispersion according to the present
invention is preferably in the range of 20 to 60% by weight, more
preferably 30 to 50% by weight. As the commercially available bead
mill, there may be mentioned a nano mill manufactured by Asada Iron
Works Co., Ltd., a ultravisco mill manufactured by AIMEX Co., Ltd.,
an Annular type OB mill manufactured by MATSUBO CORPORATION, and a
DYNO mill manufactured by Shinmaru Enterprises Corporation,
etc.
[0040] As one of the embodiments of the present invention, when
fumed silica fine particles having an average secondary particle
diameter of 500 nm or less are used in addition to the
above-mentioned precipitated silica fine particles having an
average secondary particle diameter of 500 nm or less in the
ink-receptive layer A, a ratio of the both materials to be used is
in terms of a weight ratio of preferably in the range of from 30:70
to 70:30. The reason why the precipitated silica and the fumed
silica are used in combination in the ink-receptive layer A is that
as compared with the case where the precipitated silica is used
alone, surface defect, particularly crack can be lowered when the
ink-receptive layer A and the ink-receptive layer B are subjected
to multi-layer coating and dried.
[0041] An average primary particle diameter of the fumed silica to
be contained in the ink-receptive layer A of the present invention
and in the ink-receptive layer B which is one of the embodiments of
the present invention is preferably 50 nm or less, more preferably
5 to 30 nm. When the fumed silica is to be used in the
ink-receptive layer, it is preferred that the fumed silica is
pulverized to have an average secondary particle diameter of 500 nm
or less in the presence of a cationic compound in an aqueous
medium. As an example of the cationic compound, there may be
mentioned the cationic polymer and the water-soluble metallic
compound mentioned in the explanation of pulverization of the
precipitated silica. At the time of pulverization, it is preferably
carried out the procedure until the particles become finer with an
average secondary particle diameter of 300 nm or less by using a
high-pressure homogenizer or a media mill.
[0042] The precipitated silica and the fumed silica to be used in
the ink-receptive layer A may be subjected to simultaneous
dispersion and simultaneous pulverization, but it is advantageous
in many cases to separately treat them to have optimum average
secondary particle diameters, respectively.
[0043] The lower limit values of the average secondary particle
diameter of the precipitated silica and the fumed silica are
preferably 50 nm or so, in view of the facts that an energy cost
rises in finer pulverization, or as an average secondary particle
diameter is close to an average primary particle diameter, ink
absorption property is observed to be lowered.
[0044] Alumina, and alumina hydrate to be contained in the
ink-receptive layer B of the present invention is aluminum oxide or
a hydrate thereof, which may be crystalline or non-crystalline, and
those having irregular, sphere, or plate shaped, etc. are used.
Either of which may be used and both of them may be used in
combination.
[0045] As the alumina of the present invention, .gamma.-alumina
which is .gamma. type crystal of aluminum oxide is preferred, of
these, .delta. group crystal is preferred. In .gamma.-alumina, it
is possible to make a primary particle as small as 10 nm or so, and
generally those in which secondary particle crystals having several
thousands to several ten-thousands are pulverized to 50 to 300 nm
or so by ultrasonic wave, a high pressure homogenizer, an opposed
or mutual collision type jet pulverizer, etc., are preferably
used.
[0046] Alumina hydrate of the present invention can be represented
by the formula Al.sub.2O.sub.3.nH.sub.2O. The alumina hydrate can
be classified due to the difference in composition or crystal form
into gibbsite, bayerite, norstrandite, boehmite, boehmite gel
(pseudoboehmite), diaspore, amorphous non-crystalline, etc. Of
these, in the above-mentioned formula, when the value of n is 1, it
represents alumina hydrate with a boehmite structure, when n
exceeds 1 and less than 3, it represents alumina hydrate with a
pseudoboehmite structure, and when n is 3 or more, it represents
alumina hydrate with a non-crystalline structure. In particular,
the alumina hydrate preferably used in the present invention is
alumina hydrate with a pseudoboehmite structure where n exceeds 1
and less than 3. The alumina hydrate can be obtained by the
conventionally known preparation methods such as hydrolysis of
aluminum alkoxide such as aluminum isopropoxide, etc.,
neutralization of an aluminum salt by an alkali, hydrolysis of
aluminate, etc.
[0047] A shape of the alumina hydrate to be used in the present
invention may be either of a platy, fibrous, needle, shpere, rod
shape, etc., and a preferred shape in view of the ink absorption
property is a platy with an aspect ratio of 2 or more. It is
preferably an average aspect ratio of 3 to 6. The aspect ratio is
represented by a ratio of "a diameter" relative to "a thickness" of
the particle. Here, the diameter of the particle means a diameter
of a circle with an equal projected surface area of the particle of
alumina hydrate when it is observed by an electron microscope. When
the aspect ratio is less than 2, fine pore size distribution of the
ink-receptive layer becomes narrow, and the ink absorption property
is lowered. On the other hand, when the aspect ratio exceeds 8, it
becomes difficult to prepare alumina hydrate with a uniform grain
size.
[0048] The average primary particle diameter of the fumed silica,
precipitated silica, alumina and alumina hydrate of the present
invention can be obtained from an observation by an electron
microscope where the particles are dispersed, and for each of 100
particles existing in a predetermined area, a primary particle
diameter of a circle whose area is equivalent to a projected area
of each particle is taken as a primary particle diameter for that
particle, and these values are averaged. The average secondary
particle diameter of the fumed silica, precipitated silica, alumina
and alumina hydrate of the present invention can be obtained by
measuring a dilute dispersion with a laser diffraction/scatter type
particle size distribution measurement device.
[0049] In the present invention, the hydrophilic binder to be used
in combination with the inorganic fine particles in the
ink-receptive layer is mainly a polyvinyl alcohol, and preferably a
completely or partially saponified polyvinyl alcohol or a
cation-modified polyvinyl alcohol.
[0050] Preferred completely or partially saponified polyvinyl
alcohol is a partially or completely sapoinified one with a
saponification degree of 80% or more, and an average polymerization
degree of 200 to 5000. Also, as the cation-modified polyvinyl
alcohol, there may be mentioned, for example, a polyvinyl alcohol
having a primary to tertiary amino group or a quaternary ammonium
group at the main chain or a side chain of the polyvinyl alcohol as
disclosed in Japanese Unexamined Patent Publication No.
sho.61-10483.
[0051] In the present invention, other hydrophilic binders than
those as mentioned above may be used in combination, but the amount
thereof is preferably 20 parts by weight or less based on 100 parts
by weight of the polyvinyl alcohol.
[0052] In the present invention, other cross-linking agent (film
hardener) may be used in combination with the above-mentioned
hydrophilic binder. Specific examples of the cross-linking agent
may include an aldehyde type compound such as formaldehyde and
glutaraldehyde, a ketone compound such as diacetyl and
chloropentanedione, a compound having a reactive halogen such as
bis(2-chloroethylurea), 2-hydroxy-4,6-dichloro-1,3,5-triazine, and
those as disclosed in U.S. Pat. No. 3,288,775, divinylsulfone, a
compound having a reactive olefin as disclosed in U.S. Pat. No.
3,635,718, a N-methylol compound as disclosed in U.S. Pat. No.
2,732,316, an isocyanate compound as disclosed in U.S. Pat. No.
3,103,437, an aziridine compound as disclosed in U.S. Pat. No.
3,017,280 and U.S. Pat. No. 2,983,611, a carbodiimide type compound
as disclosed in U.S. Pat. No. 3,100,704, an epoxy compound as
disclosed in U.S. Pat. No. 3,091,537, a halogen carboxyaldehyde
compound such as mucochloric acid, a dioxane derivative such as
dihydroxy-dioxane, an inorganic cross-linking agent such as
chromium alum, zirconium sulfate, boric acid, a borate and borax,
and they may be used independently or in combination of two or
more. Of these, boric acid or a borate are particularly preferred.
Boric acid to be used in the present invention may include
ortho-boric acid, meta-boric acid, hypoboric acid, etc., and the
borate may include a sodium salt, a potassium salt or an ammonium
salt of the above-mentioned materials.
[0053] By using a polyvinyl alcohol and boric acid or a borate as a
film-hardening agent in the lower side ink-receptive layer A, good
surface glossiness and high ink absorption property can be
obtained, and blur after printing can be made little. It can be
considered that by adding boric acid or a borate, fine cracks in
the lower side ink-receptive layer can be prevented, which affects
to the surface glossiness of the upper side ink-receptive layer B,
to give a recording material having high surface glossiness.
[0054] In the ink-receptive layer A of the present invention, an
amount of the polyvinyl alcohol to be used shall be made less than
20 parts by weight based on 100 parts by weight of the precipitated
silica fine particles or the precipitated silica fine particles and
the fumed silica fine particles, preferably 8 to 19 parts by
weight. By making the above-mentioned range, high ink absorption
property can be obtained. Also, in the ink-receptive layer A of the
present invention, a content of the boric acid or the borate based
on 100 parts by weight of the polyvinyl alcohol is preferably 0.02
to 50 parts by weight, more preferably 0.5 to 35 parts by
weight.
[0055] In the ink-receptive layer B of the present invention, an
amount of the polyvinyl alcohol to be used is required to be less
than 25 parts by weight based on 100 parts by weight of the fumed
silica, alumina or alumina hydrate, more preferably in the range of
8 to 24 parts by weight. By making the above-mentioned range, high
surface glossiness, sufficient surface strength, and good ink
absorption property can be obtained. When it is added in an amount
of 25 parts by weight or more, ink absorption property is markedly
lowered. In the ink-receptive layer B of the present invention, a
content of the boric acid or the borate based on 100 parts by
weight of the polyvinyl alcohol is preferably 0.005 to 50 parts by
weight, more preferably 0.01 to 30 parts by weight.
[0056] A dried coating amount of the ink-receptive layer A is
preferably in the range of 8 to 40 g/m.sup.2, more preferably 10 to
30 g/m.sup.2. This range is preferred in view of an ink absorption
property, coloring property, and blur after printing. Also, a dried
coating amount of the ink-receptive layer B is preferably in the
range of 0.5 to 18 g/m.sup.2, more preferably 1 to 10 g/m.sup.2.
The above-mentioned range is preferred in view of surface
glossiness, coloring property, and blur after printing. Of these, a
dried coating amount of the ink-receptive layer B when fumed silica
is contained in the ink-receptive layer B is preferably in the
range of 0.2 to 4 g/m.sup.2, particularly preferably 0.5 to 4
g/m.sup.2 in terms of an amount of the fumed silica. The
above-mentioned range is preferred in view of ink absorption
property, coloring property, and resistance to crack by
folding.
[0057] A sum of the dried coating amounts of the ink-receptive
layer A and the ink-receptive layer B is preferably 12 to 45
g/m.sup.2, more preferably 15 to 30 g/m.sup.2. The above-mentioned
range is preferred in view of ink absorption property and strength
of the ink-receptive layer.
[0058] The respective ink-receptive layers of the present invention
preferably further contain a cationic compound for the purpose of
improving water resitance, etc. Examples of the cationic compound
may be mentioned the cationic polymer and the water-soluble
metallic compound mentioned in the explanation of pulverization of
the precipitated silica. In particular, a cationic polymer with a
molecular weight of 5,000 to 100,000 or so, and a compound
comprising aluminum a metal of Group 4A (for example, zirconium,
titanium) of the Periodic Table are preferred. The cationic
compound may be used alone or may be used in combination of a
plural number of compounds in combination.
[0059] In the present invention, to the respective ink-receptive
layers, in addition to a surfactant and a film-hardening agent,
various kinds of conventionally known additives such as a coloring
dye, a coloring pigment, a fixing agent of an ink dye, an UV
absorber, an antioxidant, a dispersing agent of the pigment, a
defoaming agent, a leveling agent, an antiseptic agent, a
fluorescent brightner, a viscosity stabilizer, a pH controller,
etc. may be further added.
[0060] In the present invention, as the ink-receptive layer, other
layer(s) may be provided other than the ink-receptive layers A and
B, and in this case, it is necessary to be a layer which does not
impair ink permeation property. For example, for the purpose of
improving flaw resistance, it is preferred to provide a protective
layer mainly comprising colloidal silica on the ink-receptive layer
with an extent that it does not lower ink absorption property, for
example, with a coating amount of about 5 g/m.sup.2 or less in a
solid content. An average particle diameter of the primary
particles of the colloidal silica in general is 5 to 100 nm or so,
and it is preferred to form secondary particles with an average
particle diameter of 10 to 500 nm or so in view of ink absorption
property. As a commercially available spherical silica, there may
be mentioned SNOWTEX 20, etc., available from Nissan Chemical
Industries, Ltd., cataloid USB, etc., available from CATALYSTS
& CHEMICALS IND. CO., LTD., as a chain state, there may be
mentioned SNOWTEX UP, etc., available from Nissan Chemical
Industries, Ltd., and as a pearl necklace shape, there may be used
SNOWTEX PS-M, etc., available from Nissan Chemical Industries, Ltd.
Also, colloidal silica in which the surface of the colloidal silica
is modified to cationic can be preferably used, of these, it is
preferred that the surface of which is cationically modified by an
aluminum compound. As the alumina-modified colloidal silica, there
may be mentioned SNOWTEX AK-L, SNOWTEX AK-UP, SNOWTEX PS-M-AK,
etc., available from Nissan Chemical Industries, Ltd.
[0061] In the present invention, a coating method of the respective
layers constituting the ink-receptive layer can be used those
coating methods conventionally known in the art. There may be
mentioned, for example, a slide bead system, a curtain system, an
extrusion system, an air knife system, a roll coating system, a rod
bar coating system, etc.
[0062] In the present invention, by coating respective layers which
constitute the ink-receptive layer such as the ink-receptive layer
A, B, etc., substantially simultaneously without providing a drying
step with a slide bead system, etc., characteristics required for
the respective layers can be obtained with good efficiency, and
this is preferred in the point of production efficiency. That is,
by laminating the respective layers in a wet condition, the
components contained in the respective layers are difficultly
permeated into the lower layer, so that it can be expected that the
constitution of the components of the respective layers can be well
maintained after drying.
[0063] When a coating solution of the ink-receptive layer is coated
on a film support or a resin-coated paper, a corona discharge
treatment, a flame treatment, an untraviolet ray irradiation
treatment, a plasma treatment, etc., is/are carried out prior to
the coating.
[0064] In the present invention, when a support is used, in
particular, a film or a resin-coated paper which is a
water-resistant support is used, it is preferred to provide a
primer layer mainly comprising a natural polymer compound or a
synthetic resin on a surface on which the ink-receptive layer is to
be provided. On the primer layer, an ink-receptive layer containing
inorganic fine particles of the present invention is coated, then,
it is cooled, and dried at a relatively low temperature,
transparency of the ink-receptive layer is further improved.
[0065] The primer layer provided on the support mainly comprises a
natural polymer compound such as gelatin, casein, etc., or a
synthetic resin. Such a synthetic resin may be mentioned an acrylic
resin, a polyester resin, vinylidene chloride, a vinyl chloride
resin, a vinyl acetate resin, polystyrene, a polyamide resin, a
polyurethane resin, etc.
[0066] The above-mentioned primer layer is provided on the support
with a thickness (dry film thickness) of 0.01 to 5 .mu.m. It is
preferably in the range of 0.05 to 5 .mu.m.
[0067] To the support of the present invention, various kinds of
back coating layers can be provided by coating for the purpose of
writing property, anti-static property, conveying property,
anti-curl property, etc. To the back coating layer, an inorganic
antistatic agent, an organic antistatic agent, a hydrophilic
binder, latex, pigment, a curing agent, a surfactant, etc., may be
contained with an optional combination.
EXAMPLE
[0068] In the following, the present invention will be explained in
more detail by referring to Examples, but the contents of the
present invention are not limited by Examples. Incidentally, all
part(s) and % mean part(s) by weight and % by weight, respectively,
otherwise specifically mentioned.
Example 1
<Preparation of Paper Support Coated with Polyolefin
Resin>
[0069] A mixture of a bleached kraft pulp of hardwood (LBKP) and a
bleached sulfite pulp of softwood (NBSP) with a ratio of 1:1 was
subjected to beating until it becomes 300 ml by the Canadian
Standard Freeness to prepare a pulp slurry. To the slurry were
added alkyl ketene dimer in an amount of 0.5% based on the amount
of the pulp as a sizing agent, polyacrylamide in an amount of 1.0%
based on the same as a strengthening additive of paper, cationic
starch in an amount of 2.0% based on the same, and a polyamide
epichlorohydrin resin in an amount of 0.5% based on the same, and
the mixture was diluted with water to prepare a slurry with a
concentration of 1%. This slurry was made paper by a tourdrinier
paper machine to have a basis weight of 170 g/m.sup.2, dried and
subjected to moisture conditioning to prepare a base paper for a
polyolefin resin-coated paper. A polyethylene resin composition
comprising a low density polyethylene having a density of 0.918
g/cm.sup.3 and 10% of anatase type titanium oxide based on the low
density polyethylene and dispersed uniformly in the resin was
melted at 320.degree. C. and the melted resin composition was
subjected to extrusion coating on a surface of the above-mentioned
base paper with a thickness of 35 .mu.m by 200 m/min and subjected
to extrusion coating by using a cooling roller subjected to
slightly roughening treatment to make a resin-coated paper surface.
On the other surface of the base paper, a blended resin composition
comprising 70 parts by weight of a high density polyethylene resin
having a density of 0.962 g/cm.sup.3 and 30 parts by weight of a
low density polyethylene resin having a density of 0.918 g/cm.sup.3
was melted similarly at 320.degree. C. and the melted resin
composition was subjected to extrusion coating with a thickness of
30 .mu.m and subjected to extrusion coating by using a cooling
roller subjected to roughening treatment to make a resin-coated
paper back surface.
[0070] Onto the front surface of the above-mentioned polyolefin
resin-coated paper was subjected to a high frequency corona
discharge treatment, and then, a coating solution for forming a
subbing layer having the composition mentioned below was coated
thereon to have a gelatin amount of 50 mg/m.sup.2 and dried to
prepare a support. TABLE-US-00001 <Subbing layer composition>
Lime-treated gelatin 100 parts 2-Ethylhexyl sulfosuccinate 2 parts
Chromium alum 10 parts
<Precipitated Silica Dispersion 1>
[0071] To water were added 4 parts of a dimethyldiallyl ammonium
chloride homopolymer (molecular weight: 9,000) and 100 parts of
precipitated silica (average primary particle diameter: 15 nm,
average secondary particle diameter: 23 .mu.m, oil absorption
amount: 185 ml/100 g) to prepare a provisional dispersion by using
a saw blade type dispersing device (blade rim speed: 30 m/sec).
Next, the obtained provisional dispersion was passed once through a
bead mill under the conditions of zirconia beads with a diameter of
0.3 mm, a filling rate of 80% by volume and a disc rim speed of 10
m/sec to prepare Precipitated silica dispersion 1 with a solid
concentration of 30% and an average secondary particle diameter of
200 nm.
<Precipitated Silica Dispersion 2>
[0072] To water were added 4 parts of a dimethyldiallyl ammonium
chloride homopolymer (molecular weight: 9,000) and 100 parts of
precipitated silica (average primary particle diameter: 11 nm,
average secondary particle diameter: 3 .mu.m, oil absorption
amount: 220 ml/100 g), and the mixture was dispersed by using a saw
blade type dispersing device (blade rim speed: 30 m/sec) to prepare
a provisional dispersion. Next, the obtained provisional dispersion
was passed once through a bead mill under the conditions of
zirconia beads with a diameter of 0.3 mm, a filling rate of 80% by
volume and a disc rim speed of 10 m/sec to prepare Precipitated
silica dispersion 2 with a solid concentration of 15% and an
average secondary particle diameter of 200 nm.
<Fumed Silica Dispersion>
[0073] To water were added 4 parts of a dimethyldiallyl ammonium
chloride homopolymer (molecular weight: 9,000) and 100 parts of
fumed silica (average primary particle diameter: 7 nm), and the
mixture was dispersed by using a saw blade type dispersing device
(blade rim speed: 30 m/sec) to prepare a provisional dispersion.
Next, the obtained provisional dispersion was passed once through a
pressure homogenizer under the conditions of 40 MPa to prepare
fumed silica dispersion with a solid concentration of 20% and an
average secondary particle diameter of 150 nm.
[0074] Recording Material 1 (Present Invention)
[0075] On the surface of the above-mentioned support were
simultaneously coated a coating solution for an ink-receptive layer
A1 and a coating solution for an ink-receptive layer B1 having the
compositions mentioned below so that dried coating amounts of
silica of the ink-receptive layer A1 being 23 g/m.sup.2, and that
of the ink-receptive layer B1 being 2 g/m.sup.2, by using a slide
bead coating device, and dried to prepare Recording material 1.
Incidentally, the ink-receptive layer A1 is a lower layer nearer to
the support, and the ink-receptive layer B1 is an upper layer. The
drying conditions after the coating were that the coated material
was cooled at 0.degree. C. for 30 seconds, at 42.degree. C. under
10% RH until the concentration of the total solid content became
90%, and then, at 35.degree. C. under 10% RH. TABLE-US-00002
<Composition for Ink-receptive layer A1> Precipitated silica
dispersion 1 (as a silica solid 100 parts content) Boric acid 2.5
parts Polyvinyl alcohol 15 parts (Saponification degree: 88%,
average polymerization degree: 3500) Surfactant 0.1 part
Methylolmelamine series compound 3 parts (BECKAMINE PM-N available
from DAINIPPON INK AND CHEMICALS, INCORPORATED) <Composition for
Ink-receptive layer B1> Fumed silica dispersion (as a silica
solid content) 100 parts Boric acid 5 parts Polyvinyl alcohol 20
parts (Saponification degree: 88%, average polymerization degree:
3500) Surfactant 0.5 part
[0076] Recording Material 2 (Present Invention)
[0077] The coating solution for the ink-receptive layer A1 and the
coating solution for the ink-receptive layer B1 were coated in the
same manner as in Recording material 1 except for changing the
dried coating amounts of silica of the ink-receptive layer A1 being
18 g/m.sup.2, and that of the ink-receptive layer B1 being 7
g/m.sup.2, to prepare Recording material 2.
[0078] Recording Material 3 (Present Invention)
[0079] In the same manner as in Recording material 1 except for
using Precipitated silica dispersion 2 in place of Precipitated
silica dispersion 1 in the composition for the ink-receptive layer
A1, Recording material 3 was prepared.
[0080] Recording Material 4 (Comparative Example)
[0081] In the same manner as in Recording material 1 except for not
coating the coating solution for the ink-receptive layer A1, and
coating the coating solution for the ink-receptive layer B1 alone
with the dried coating amount of silica of 25 g/m.sup.2, Recording
material 4 was prepared.
[0082] Recording Material 5 (Comparative Example)
[0083] In the same manner as in Recording material 1 except for not
coating the coating solution for ink-receptive layer B1 , and
coating the coating solution for the ink-receptive layer A1 alone
with the dried coating amount of silica of 25 g/m.sup.2, Recording
material 5 was prepared.
[0084] Recording Material 6 (Comparative Example)
[0085] In the same manner as in Recording material 1 except for
changing the added amount of the polyvinyl alcohol to 25 parts and
the added amount of the boric acid to 4.2 parts in the composition
of the ink-receptive layer A1, Recording material 6 was
prepared.
[0086] Recording material 7 (Comparative example) In the same
manner as in Recording material 1 except for changing the added
amount of the polyvinyl alcohol to 27 parts and the added amount of
the boric acid to 6 parts in the composition of the ink-receptive
layer B1, Recording material 7 was prepared.
[0087] Recording Material 8 (Comparative Example)
<Precipitated Silica Dispersion 3>
[0088] In the same manner as in Precipitated silica dispersion 1
except for changing the diameter of zirconia beads from 0.3 mm to 3
mm in the provisional dispersion of the precipitated silica,
Precipitated silica dispersion 3 having a concentration of the
solid content of 30% and an average secondary particle diameter of
800 nm was prepared.
[0089] Next, the same procedure was carried out as in Recording
material 1 except for using Precipitated silica dispersion 3 in
place of Precipitated silica dispersion 1 in the composition of the
ink-receptive layer A1, Recording material 8 was prepared.
[0090] With regard to the ink-jet recording materials prepared as
mentioned above, the following evaluations were carried out. The
results are shown in Table 1.
<Ink Absorption Property>
[0091] Cyan, magenta or yellow single color with 100% and a
threefold color with 300% were each printed by using an ink-jet
printer (manufactured by Seiko Epson Co., PM-880C), and a PPC paper
was overlapped and slightly pressed to contact with the printed
portion immediately after the printing, and a degree of an amount
of ink transferred to the PPC paper was observed with naked eyes
and evaluated totally by the following criteria.
[0092] .circleincircle.: Completely no transfer occurred.
[0093] .largecircle.: There is no transfer at 100% portion, but
slightly transferred at 300% portion.
[0094] X: There is no transfer at 100% portion, but at 300%
portion, ink is overflown and clearly transferred to a PPC
paper.
[0095] X X: There is transfer at 100% portion.
<Coloring Property>
[0096] An image including scenery and a person was printed by using
an ink-jet printer (manufactured by Seiko Epson Co., PM-880C), and
feeling looked with eyes was judged by the following criteria.
[0097] .largecircle.: It has a feeling as that of a color
photography.
[0098] .DELTA.: It is slightly inferior to that of a color
photography.
[0099] X: It is clearly inferior to that of a color
photography.
[0100] X X: It is markedly inferior to that of a color
photography.
[0101] Incidentally, in Recording material 6, ink was overflown so
that this evaluation could not be carried out.
<Resistance to Crack by Folding>
[0102] Recording materials were each subjected to seasoning under
the conditions of at 10.degree. C. and 20% RH for 24 hours, and
crack by folding was judged under the same temperature and same
humidity conditions. The judgement method is a method that the
recording material was cut to a length of 12 cm, and the
ink-receptive layer was placed at an outer side, bending it in an
arc shape and a diameter of the arc at which a crushed sound could
be heard was measured. The smaller numerical value, that is, the
smaller diameter means better resistance to crack by folding and
shows that the material difficultly causes crack by folding. Since
a product rolled to 2-inch core in a rolled state has been
commercially available, it is necessary to show a numerical value
of at least 50 mm or less for practical use. TABLE-US-00003 TABLE 1
Resistance Ink to crack by absorption Coloring folding property
property (mm) Recording material 1 .circleincircle. .largecircle.
38 (Present invention) Recording material 2 .circleincircle.
.largecircle. 45 (Present invention) Recording material 3
.circleincircle. .DELTA. 40 (Present invention) Recording material
4 .circleincircle. .largecircle. 67 (Comparative example) Recording
material 5 .circleincircle. X 35 (Comparative example) Recording
material 6 X .largecircle. 34 (Comparative example) Recording
material 7 XX -- 42 (Comparative example) Recording material 8
.largecircle. XX 32 (Comparative example)
[0103] From the above-mentioned results, it can be understood that
the ink-jet recording materials of the present invention have good
ink absorption property and coloring property, and excellent in
resistance to crack by folding.
[0104] Recording Material 9 (Present Invention)
[0105] A coating solution for an ink-receptive layer C1 having the
composition shown below was prepared, and on the surface of the
support and from the side nearer to the support, the coating
solution for the ink-receptive layer A1, the coating solution for
the ink-receptive layer B1 , and the coating solution for the
ink-receptive layer C1 were simultaneously coated in this order by
using a slide bead coating device, and dried to prepare Recording
material 9. Temperature conditions at the time of drying are the
same as in the preparation of Recording material 1. Dried coating
amount of silica in the respective layers were so coated that the
ink-receptive layer A1 was 23 g m.sup.2, the ink-receptive layer B1
was 2 g/.sup.2m , and the ink-receptive layer C1 was 1 g/m.sup.2.
TABLE-US-00004 <Composition for Ink receptive layer C1>
Colloidal silica (as a silica solid content) 100 parts (available
from Nissan Chemical Industries, Ltd., SNOWTEX AK-L, average
primary particle diameter: 40 nm) Polyvinyl alcohol 5 parts
(saponification degree: 88%, average polymerization degree: 3500)
Surfactant 0.3 part
[0106] The above-mentioned Recording material 9 had the same ink
absorption property, coloring property and resistance to crack by
folding as those of Recording material 1. Moreover, with regard to
glossiness and flaw resistance, it was excellent than those of
Recording material 1. With regard to the flaw resistance, the
ink-jet recording material was cut with a size of 3 cm.times.4 cm,
1200 g of a weight was adhered to a surface opposite to the
printing surface, and the sample adhered to the weight was placed
on a PPC paper by making the printing surface down, the sample
adhered to the weight was pulled with a rate of 50 cm/min for 20
cm, and disturbance of an image at the printed portion and a
transferred degree to the PPC paper were judged with naked eyes and
evaluated.
[0107] From the above-mentioned results, it can be understood that
by providing a layer mainly containing colloidal silica at the
layer farther from the support, the resulting material has good ink
absorption property, coloring property and resistance to crack by
folding, and further is high glossiness and excellent in flaw
resistance.
Example 2
[0108] Recording Material 10 (Present Invention)
[0109] On the surface of the above-mentioned support were
simultaneously coated a coating solution for an ink-receptive layer
A2 and a coating solution for an ink-receptive layer B2 having the
compositions mentioned below so that dried coating amounts of
silica of the ink-receptive layer A2 being 20 g/m.sup.2, and that
of the ink-receptive layer B2 being 4 g/m.sup.2, by using a slide
bead coating device, and dried to prepare Recording material 10.
The ink-receptive layer A2 is a lower layer nearer to the support,
and the ink-receptive layer B2 is an upper layer. The drying
conditions after the coating were that the coated material was
cooled at 5.degree. C. for 30 seconds, at 45.degree. C. under 10%
RH until the concentration of the total solid content became 90%,
and then, at 35.degree. C. under 10% RH. TABLE-US-00005
<Ink-receptive layer A2 composition> Precipitated silica
dispersion 1 (as a 100 parts silica solid content) Boric acid 3
parts Polyvinyl alcohol 15 parts (Saponification degree: 88%,
average polymerization degree: 3500) Surfactant 0.3 part
<Ink-receptive layer B2 composition> Pseudoboehmite 100 parts
(Average primary particle diameter: 14 nm, average secondary
particle diameter 160 nm, rectangular shaped particles) Boric acid
0.5 part Polyvinyl alcohol 12 parts (Saponification degree 88%,
average polymerization degree 3500) Surfactant 0.3 part
[0110] Recording Material 11 (Present Invention)
[0111] In the same manner as in Recording material 10 except for
changing the dried coated amount of the solid contents in Example 1
of the ink-receptive layer A2 being 12 g/m.sup.2, and that of the
ink-receptive layer B2 being 12 g/m.sup.2, to prepare Recording
material 11.
[0112] Recording Material 12 (Present Invention)
<Precipitated Silica Dispersion 4>
[0113] In the same manner as in Precipitated silica dispersion 1
except for changing the bead mill conditions to alkali-free glass
beads with a diameter of 1 mm, a filling ratio of 70% and a disc
rim speed of 10 m/sec, Precipitated silica dispersion 4 with a
concentration of the solid content of 30% and an average secondary
particle diameter of 320 nm was prepared.
[0114] Next, in the same manner as in Recording material 10 except
for changing Precipitated silica dispersion 1 to Precipitated
silica dispersion 4 in the above-mentioned ink-receptive layer A2
composition, Recording material 12 was prepared.
[0115] Recording Material 13 (Present Invention)
[0116] In the same manner as in Recording material 10 except for
changing the pseudoboehmite to platy pseudoboehmite having an
average primary particle diameter of 15 nm and an aspect ratio of 5
in the composition for the ink-receptive layer B2, Recording
material 13 was prepared.
[0117] Recording Material 14 (Present Invention)
[0118] In the same manner as in Recording material 10 except for
changing the pseudoboehmite to .gamma.-alumina having an average
primary particle diameter of 13 nm in the ink-receptive layer B2
composition, Recording material 14 was prepared.
[0119] Recording Material 15 (Present Invention)
[0120] In the same manner as in Recording material 10 except for
using Precipitated silica dispersion 2 in place of Precipitated
silica dispersion 1 in the composition for the ink-receptive layer
A2, Recording material 15 was prepared.
[0121] Recording Material 16 (Present Invention)
[0122] In the same manner as in Recording material 1 except for
changing the composition for the ink-receptive layer A2 to the
composition mentioned below, Recording material 16 was prepared.
TABLE-US-00006 <Composition for Ink-receptive layer A3>
Precipitated silica dispersion 1 100 parts (as a silica solid
content) Boric acid 3 parts Polyvinyl alcohol 15 parts
(Saponification degree 88%, average polymerization degree 3500)
Basic poly(aluminum hydroxide) 3 parts Surfactant 0.3 part
[0123] Recording Material 17 (Present Invention)
[0124] A coating solution for an ink-receptive layer C2 having the
composition shown below was prepared, and on the surface of the
support and from the side nearer to the support, the coating
solution for the ink-receptive layer A2, the coating solution for
the ink-receptive layer B2, and the coating solution for the
ink-receptive layer C2 were simultaneously coated in this order by
using a slide bead coating device, and dried to prepare Recording
material 17. Temperature conditions at the time of drying are the
same as in the preparation of Recording material 10. Dried coating
amount of silica in the respective layers were so coated that the
ink-receptive layer A4 was 20 g/m.sup.2, the ink-receptive layer B3
was 3 g/m.sup.2, and the ink-receptive layer C2 was 1 g/m.sup.2.
TABLE-US-00007 <Ink receptive layer C2 composition> Colloidal
silica (as a silica solid content) 100 parts (Available from Nissan
Chemical Industries, Ltd., SNOWTEX AK-L, average primary particle
diameter: 40 nm) Polyvinyl alcohol 5 parts (Saponification degree
88%, average polymerization degree 3500) Boric acid 2 parts
Surfactant 0.3 part
[0125] Recording Material 18 (Comparative Example)
[0126] In the same manner as in Recording material 10 except for
not coating the coating solution for the ink-receptive layer B2,
and coating the coating solution for the ink-receptive layer A2
alone with the dried coating amount of the solid content at drying
of 24 g/m.sup.2, Recording material 18 was prepared.
[0127] Recording Material 19 (Comparative Example)
[0128] In the same manner as in Recording material 10 except for
not coating the coating solution for the ink-receptive layer A2,
and coating the coating solution for the ink-receptive layer B2
alone with the dried coating amount of the solid content at drying
of 24 g/m.sup.2, Recording material 19 was prepared.
[0129] Recording Material 20 (Comparative Example)
[0130] In the same manner as in Recording material 10 except for
changing silica dispersion 1 (silica solid content) to precipitated
silica (average secondary particle diameter: 2 .mu.m) which had
been used without pulverization in the composition for the
ink-receptive layer A2, Recording material 20 was prepared.
[0131] Recording Material 21 (Comparative Example)
[0132] In the same manner as in Recording material 10 except for
using gel method silica (average secondary particle diameter: 300
nm) in place of silica dispersion 1 (silica solid content) in the
composition for the ink-receptive layer A2, Recording material 21
was prepared.
[0133] Recording Material 22(Comparative Example)
[0134] In the same manner as in Recording material 10 except for
changing the composition for the ink-receptive layer A2 to the
composition mentioned below, Recording material 22 was prepared.
TABLE-US-00008 <Ink-receptive layer A4 composition> Fumed
silica (average primary particle diameter 20 nm) 100 parts
Dimethylallyl ammonium chloride homopolymer 4 parts Boric acid 4
parts Polyvinyl alcohol 20 parts (Saponification degree 88%,
average polymerization degree 3500) Surfactant 0.1 part
[0135] With regard to the ink-jet recording materials prepared as
mentioned above, the following evaluations were carried out. The
results are shown in Table 2.
<Ink Absorption Property>
[0136] By using a commercially available ink-jet printer
(manufactured by Canon Inc., BJF-870), solid printing with red,
blue, green or black color was each carried out, and immediately
after the printing, a PPC paper was overlapped over the printed
portion with a slight pressurization, and the degree of an amount
of the ink transferred to the PPC paper was observed with naked
eyes. It was totally evaluated by the following criteria.
[0137] .circle-w/dot.: No transfer was observed.
[0138] .largecircle.: Slight transfer was observed but practically
used.
[0139] .DELTA.: Dark transfer was observed and practical use is
difficult.
[0140] X: Ink was transferred on the whole surface and practical
use is impossible.
<Coloring Property>
[0141] Solid printing with each color of cyan, magenta, yellow and
black was carried out, and an optical density was measured by a
Macbeth reflection densitometer, and the sum of the optical density
of the respective colors was shown. The larger numerical value
means good coloring property.
<Glossiness at White Paper Portion>
[0142] Glossiness at the white paper portion of the recording
material before printing was observed with inclined light and
evaluated by the following criteria.
[0143] .circle-w/dot.: It possesses high glossy feeling as that of
a color photography.
[0144] .largecircle.: There is a glossy feeling, but slightly
inferior to .COPYRGT..
[0145] .DELTA.: There is a glossy feeling as that of an art paper
or a coated paper.
[0146] X: There is a low glossy feeling as that of uncoated
paper.
<Blur at Preservation>
[0147] After printing an image, the sample preserved for a week in
an alubum for photography was observed with naked eyes and judged
by the following criteria.
[0148] .circle-w/dot.: No blur was observed.
[0149] .largecircle.: Slight blur was admitted.
[0150] .DELTA.: Blur was admitted.
[0151] X: Remarkably blurred. TABLE-US-00009 TABLE 2 Glossiness at
Ink white Blur at absorption Coloring paper presser- property
property portion vation Recording material 10 .circleincircle. 9.0
.circleincircle. .largecircle. (Present invention) Recording
material 11 .largecircle. 8.7 .circleincircle. .largecircle.
(Present invention) Recording material 12 .circleincircle. 8.1
.largecircle. .largecircle. (Present invention) Recording material
13 .circleincircle. 8.9 .circleincircle. .circleincircle. (Present
invention) Recording material 14 .circleincircle. 8.5 .largecircle.
.largecircle. (Present invention) Recording material 15
.circleincircle. 7.9 .circleincircle. .largecircle. (Present
invention) Recording material 16 .circleincircle. 9.0
.circleincircle. .circleincircle. (Present invention) Recording
material .circleincircle. 8.9 .circleincircle. .circleincircle. 17
(Present invention) Recording material 18 .circleincircle. 7.8
.largecircle. .DELTA. (Comparative example) Recording material 19 X
8.9 .circleincircle. X (Comparative example) Recording material 20
.circleincircle. 6.9 X X (Comparative example) Recording material
21 .largecircle. 7.8 .largecircle. .DELTA. (Comparative example)
Recording material 22 .circleincircle. 8.0 .circleincircle. X
(Comparative example)
[0152] From the above-mentioned results, it can be understood that
the ink-jet recording materials of the present invention have good
ink absorption property and white paper portion glossiness,
excellent in coloring property, and less generating blur during
preservation.
Example 3
[0153] Recording material 23 (Present invention) On the surface of
the above-mentioned support were simultaneously coated a coating
solution for an ink-receptive layer A5 having the composition
mentioned below and the coating solution for the ink-receptive
layer B1 so that dried coating amounts of silica of the
ink-receptive layer A5 being 20 g/m.sup.2, and that of the
ink-receptive layer B1 being 4 g/m.sup.2, by using a slide bead
coating device, and dried to prepare Recording material 23. The
ink-receptive layer AS is a lower layer nearer to the support, and
the ink-receptive layer B1 is an upper layer. The drying conditions
after the coating were that the coated material was cooled at
5.degree. C. for 30 seconds, at 45.degree. C. under 10% RH until
the concentration of the total solid content became 90%, and then,
at 35.degree. C. under 10% RH. TABLE-US-00010 <Ink-receptive
layer A5 composition> Precipitated silica dispersion 1 (as
silica solid 50 parts component) Fumed silica dispersion (as silica
solid component) 50 parts Boric acid 3 parts Polyvinyl alcohol 15
parts (Saponification degree: 88%, average polymerization degree:
3500) Surfactant 0.3 part
[0154] Recording Material 24 (Present Invention)
[0155] In the same manner as in Recording material 23 except for
changing the ratio of Precipitated silica dispersion 1 and the
fumed silica dispersion in the composition of the ink-receptive
layer AS to 30:70 as the solid content, Recording material 24 was
prepared.
[0156] Recording Material 25 (Present Invention)
[0157] In the same manner as in Recording material 23 except for
changing the ratio of Precipitated silica dispersion 1 and the
fumed silica dispersion in the composition of the ink-receptive
layer AS to 70:30 as the solid content, Recording material 25 was
prepared.
[0158] Recording Material 26 (Present Invention)
[0159] In the same manner as in Recording material 23 except for
changing the composition for the ink-receptive layer B1 to the
composition for the ink-receptive layer B2, Recording material 26
was prepared.
[0160] Recording Material 27 (Present Invention)
[0161] In the same manner as in Recording material 26 except for
changing the pseudoboehmite to .gamma.-alumina having an average
primary particle diameter of 13 nm in the composition for the
ink-receptive layer B2, Recording material 27 was prepared.
[0162] Recording Material 28 (Present Invention)
[0163] In the same manner as in Recording material 23 except for
changing the silica dispersion in the composition for the
ink-receptive layer A5 to 100 parts of Precipitated silica
dispersion 1 alone (as a silica solid content), Recording material
28 was prepared.
[0164] Recording Material 29 (Comparative Example)
<Precipitated Silica Dispersion 5>
[0165] To water were added 4 parts of a dimethyldiallyl ammonium
chloride homopolymer (molecular weight: 9,000) and 100 parts of
precipitated silica (average primary particle diameter: 18 nm,
average secondary particle diameter: 2 .mu.m, oil absorption
amount: 200 ml/100 g), and the mixture was dispersed by using a saw
blade type dispersing device (blade rim speed: 30 m/sec) to prepare
Precipitated silica dispersion 5 having a concentration of the
solid content of 30% and an average secondary particle diameter of
1.8 .mu.m.
[0166] Next, in the same manner as in Recording material 23 except
for changing the silica dispersion of the composition for the
ink-receptive layer A5 to 100 parts of Precipitated silica
dispersion 5 alone (as a silica solid content), Recording material
29 was prepared.
[0167] Recording Material 30 (Comparative Example)
[0168] In the same manner as in Recording material 23 except for
changing the silica dispersion of the composition for the
ink-receptive layer A5 to 100 parts of fumed silica dispersion
alone (as a silica solid content), Recording material 30 was
prepared.
[0169] Recording Material 31 (Comparative Example)
[0170] In the same manner as in Recording material 26 except for
changing the silica dispersion of the composition for the
ink-receptive layer A5 to 100 parts of fumed silica dispersion
alone (as a silica solid content), Recording material 31 was
prepared.
[0171] With regard to the ink-jet recording sheets prepared as
mentioned above, the same evaluations as in Example 2 and the
following evaluation were carried out. The results are shown in
Table 3.
Surface Property>
[0172] .circle-w/dot.: Completely no problem.
[0173] .largecircle.: There is a slight defect but no crack was
observed.
[0174] .DELTA.: Crack can be observed.
[0175] X: There are many defects including cracks and it cannot be
practically used. TABLE-US-00011 TABLE 3 Glossi- Ink ness at
absorp- white Blur at tion Coloring paper presser Surface property
property portion vation property Recording material
.circleincircle. 8.6 .largecircle. to .circleincircle.
.largecircle. .circleincircle. 23 (Present invention) Recording
material .circleincircle. 8.7 .largecircle. to .circleincircle.
.largecircle. .circleincircle. 24 (Present invention) Recording
material .circleincircle. 8.4 .largecircle. .largecircle.
.largecircle. to .circleincircle. 25 (Present invention) Recording
material .largecircle. 9.0 .circleincircle. .circleincircle.
.circleincircle. 26 (Present invention) Recording material
.largecircle. 8.9 .circleincircle. .circleincircle.
.circleincircle. 27 (Present invention) Recording material
.circleincircle. 7.9 .largecircle. .largecircle. .DELTA. to
.largecircle. 28 (Present invention) Recording material
.circleincircle. 7.5 X X to .DELTA. .DELTA. to .largecircle. 29
(Comparative example) Recording material .circleincircle. 8.5
.largecircle. (X) X 30 (Comparative example) Recording material
.largecircle. 8.9 .circleincircle. (X) X 31 (Comparative example)
Note: (X) means that there is whisker-like blur before initiation
of the preservation for one week.
[0176] From the above-mentioned results, it can be understood that
the recording material for inkjet of the present invention has good
ink absorption property and glossiness at the white paper portion,
and excellent in coloring property, less blur at preservation and
little in surface defect.
INDUSTRIAL APPLICABILITY
[0177] According to the present invention, ink-jet recording
materials with high glossiness and excellent in ink absorption
property, coloring property and resistance to crack by folding,
less blur at the printed portion during preservation, and also
excellent in glossiness and flaw resistance can be obtained, and
surface defects such as crack by folding can be reduced.
* * * * *